I have a 94 Spirit FWD 2.5/automatic with 78k miles on it. While driving a couple weeks back it started to knock really bad and I lost power. I then idled it home. The oil light never came on. I took the engine out thinking it had to be a bad rod bearing but they all look perfectly good as do the main bearings. I pulled each cap off and it's clean as a whistle. I then checked the top end valve assembly and it's all looking good. The timing belt is good and all the marks line up too. Looking at the pistons one at a time from the bottom I don't see anything out of place when I rotate the assembly. I really didn't want to pull the head but that may be next. Any ideas what to check next?

 

Ok, so I've got an update. I popped the head off and found a bad head gasket. It was open about 1/4" between cylinders 1 and 2. Cylinder 1 was also much cleaner than the rest. I also pulled all the pistons out and they all look good as do the cylinder walls on all 4. While this does not explain the knocking I'm thinking maybe I was just hearing a bit of piston slap. Any ideas out there?